The Weekly Plant 4 March 2012

Common names: desertbells, desert bluebells, California bluebell Scientific name: Phacelia campanularia1

TAV location: Between driveway and Javelina Way in front of Sarah Dinham’s townhome.

Discussion: This showy annual has inch-long, bell-shaped blue flowers. The leaves are coarsely toothed, basal, and have dark red edges. It’s not clear if this species is native to Arizona or just to California. Some references list it as native to Maricopa and Pima Counties. Others list it as native to California only. However, it is frequently included in “desert wildflower” mixes, which may explain its appearance in Arizona and at TAV.

Phacelias2 are in the waterleaf family (Hydrophyllaceae). Most have blue-purple flowers and bloom in early spring. The 5-petaled flowers are held in a helicoid cyme, a structure typically found in the waterleaf family and also in the borage family (Boraginaceae). In a helicoid cyme, the flowers are held on a long stalk that is coiled on itself, similar to a scorpion’s tail or to the symbol used in the TAV and ASA logos. The stalk straightens as more flowers open.

Why do we care about helicoid cymes? You can use it to help you identify a plant. If you find a plant with a helicoid cyme, check your ID books for plants in the waterleaf and borage families. Many plant identification books and floras3 organize plants by families. Even some websites organize plants by family. Check out Southeastern Arizona Wildflowers (http://www.fireflyforest.com/flowers/). On that website you can View Arizona Plants by flower color, name, or family.

1 The USDA, ARS, National Genetic Resources Program Germplasm Resources Information Network - (GRIN) Online Database is the source of the currently accepted scientific name. 2 Some of these plants can cause contact dermatitis in sensitive individuals. 3 Floras are systematic accounts of the plant species of a given area (for example Arizona Flora by T.H. Kearney, et al.) and include Photos and text by Mary Welch-Keesey botanical descriptions and information on plant distribution.